DataMapper关联:如何指定包含关联行的表名？

class User
  include DataMapper::Resource

  property :id, Serial
  property :name, String

  has n, :posts
end

class Post
  include DataMapper::Resource

  property :id, Serial
  property :title, String
  property :content, Text

  belongs_to :user

  repository(:default).adapter.resource_naming_convention = lambda { |value| value.to_s }
end

user = User.get(1)
posts = user.posts(repository: :default, include: { user: { table_name: 'users' } })